Volunteers recorded 385,659 individual pieces of rubbish – equivalent to two pieces per metre.

Emma Snowden, MCS litter projects coordinator, said: "Whether you live near the coast or miles inland, we are all connected to the sea. This is a man-made problem. Every piece of litter has an owner and we all need to take responsibility to not drop litter in the first place."

Snowden said the society wanted to cut beach litter by 50% by 2015. "In order to achieve this we need to appoint lead agencies with the specific responsibility to stop marine litter and develop a marine action plan now." The society has launched an online petition calling on ministers to set up such a plan.

The survey – which was conducted during one weekend last September – showed the main source of rubbish is public litter (37.7%) followed by fishing litter (13.8%), sewage related debris/sanitary waste (6.2%) and shipping litter (1.8%).

The most common items were plastic and polystyrene pieces, along with plastic rope, plastic lids, crisp and sweet wrappers. Cotton bud sticks made up 4.6% of the recorded waste, while bits of fishing net and line made up 7.4%.

Plastic packaging and discarded fishing nets injure, entangle and drown marine wildlife including seals and dolphins, the society warned. More than 170 marine animals have been recorded mistaking plastic bags and other items for food, which can result in starvation, poisoning and fatal stomach blockages. It can also be hazardous to people and costs millions of pounds to clear up.

Neil Jacobson, head of coastal operations at the Crown Estate, which co-funded the survey, said: "Beachwatch and its thousands of volunteers continue to highlight the increasing problem of beach litter. This report makes it clear individual action is the key to encouraging everyone to keep Britain's beaches beautiful and free of litter."

Robin Wilkins, managing director of co-funders SeaFrance, said: "Along with other members of SeaFrance staff and local volunteers, I have been involved in regular beach cleans and surveys at Kingsdown. It's been quite shocking to see the levels of litter on the beach. One problem is it's the easy option to just leave your litter behind rather than take it home with you but the litter left behind impacts our coastline for generations."

The society says its annual surveys are "essential in turning the tide on litter". It says recent results have helped change laws governing disposal of waste at sea, and have forced investment in better coastal sewage treatment. The data also feeds into a project called the International Coastal Cleanup, involving more than 70 countries, organised by the Ocean Conservancy in the US.

"The government appears to have given up the fight against litter, which is now far worse on our beaches than it has been for years," said Nick Herbert, shadow environment secretary. "It's not only unpleasant for visitors but a threat to our marine wildlife too.

"The thousands of volunteers who are trying to clear up this mess are doing a fantastic job, but we need a far more concerted campaign to prevent littering in the first place. We need more responsibility from producers, better incentives to recycle things like plastic bottles and, where necessary, tougher enforcement against litterbugs."

Huw Irranca-Davies, the environment minister, said: "Litter goes in our bins, not on our beaches, and ultimately this is an issue of personal responsibility. This is a problem caused by a minority who spoil things for everyone else, and campaigns against this behaviour can help us to make this unacceptable to everyone. That's why we fund Keep Britain Tidy for anti-litter campaigns to help stamp out the problem."

In England, where more than a quarter of a million pieces of rubbish were logged, the average levels of litter increased by almost a tenth on the figures for 2007, and the problem got worse in all regions except for the north-west. Levels of rubbish in Scotland fell slightly in 2008, compared with the previous year, but were still at the highest densities in the UK, with an average 2,581 items per kilometre. Wales and Northern Ireland both saw litter levels fall slightly, but the Channel Islands saw a slight increase.